Increasing environmental awareness of contaminated commercial, private and government properties and their potential danger to onsite personnel and surrounding communities has resulted in development of various technologies to attempt to remove and safely dispose of toxic chemical contaminants present in the ground. Some of these technologies have proven to be somewhat applicable in limited situations.
One particular problem of interest relates to contamination of soils by volatile organic compounds which have been released into the ground over a period of time or were accidentally spilled in one or more isolated incidents. In either case, there is frequently a severe danger that the volatile organic compounds will migrate downwardly into the water supply. This can result in direct contamination of groundwater and adjacent fresh water wells or lateral migration into remote wells, surface water or wherein adjacent inhabited surface areas are directly exposed to toxic vapors and/or liquids. The presence and possible movement of these vapors and/or liquids in the ground may also present hazards to occupants of nearby buildings or future buildings to be constructed, or to construction and excavation workers.
Because of the acute toxic dangers presented by these contaminants, it is frequently imperative that the contaminants be promptly, efficiently and effectively removed. However, many constraints often inhibit or prevent removal. For example, if the contaminant(s) has progressed downwardly to a point where excavation of the soils is impossible, the soil must be decontaminated in situ. This restriction eliminates many existing decontamination technologies. Other impediments to decontamination by soil removal and/or soil removal and return subsequent to decontamination include the presence of natural geologic formations, such as rock formations, the presence of large buildings, foundations, parking areas, homesites and the like. Also, in instances where the contaminant has migrated down to and is in contact with an underlying water table, perched lens of water or saturated zone, many technologies have proven inadequate in achieving complete remediation.